CAJ | 학술논문

研究正交结构Ti?22Al?26Nb?1Zr合金片层组织在长期时效过程中B2相的分解、O相板条的球化等显微组织演变规律。结果表明：合金加热到B2单相区炉冷后可以获得板条组织，在(O+B2)相区700°C时效100 h以内显微组织无明显变化。但在长时时效过程中板条组织发生明显粗化。在700°C长期时效800 h时，B2相极不稳定，会在时效初期短时间内迅速发生分解。随着时效时间的延长，块状和少量板条状O相在晶界和O/BCC相界处析出并以球状形式长大。此外，在时效时间超过100 h后，会有明显的树枝状O相板条组织形成。
연구정교결구Ti?22Al?26Nb?1Zr합금편층조직재장기시효과정중B2상적분해、O상판조적구화등현미조직연변규률。결과표명：합금가열도B2단상구로랭후가이획득판조조직，재(O+B2)상구700°C시효100 h이내현미조직무명현변화。단재장시시효과정중판조조직발생명현조화。재700°C장기시효800 h시，B2상겁불은정，회재시효초기단시간내신속발생분해。수착시효시간적연장，괴상화소량판조상O상재정계화O/BCC상계처석출병이구상형식장대。차외，재시효시간초과100 h후，회유명현적수지상O상판조조직형성。
The microstructure development of lamellar structure of an orthorhombic Ti2AlNb-based Ti?22Al?26Nb?1Zr alloy, includingB2 decomposition and spheroidization ofO phase, was investigated. The results show that the lamellar structure is fabricated by heating the samples in the singleB2 phase field and cooling slowly in the furnace. Aging treatments are conducted in the (O+B2) phases field by air cooling. After aging at 700 °C for a short time within 100 h, there is no significant change of microstructures, whereas the coarsening of lamellae is observed in the long-term aged microstructure. Ti?22Al?26Nb?1Zr alloy exhibits microstructural instability including the severe dissolution ofB2 lamella, discontinuous precipitation and spheroidization of O phase during the long term aging process at 700 °C up to 800 h. In addition, a pronounced formation of branch-shapedO phase lamella is observed for the alloy aged over 100 h.